This invention relates generally to door hardware and more particularly to improved top guide pivot means for bifolding doors or panels.
The typical prior art top guide means for guiding a pair of bifolding doors or panels laterally across a door opening employs a track engaging pin or roller extending upwardly from the top edge of a non-jamb mounted guide panel of a hingedly joined pair of panels in such fashion that the open positioning of the panels is limited to one of substantially right angles with respect to the guide track. Consequently, the door opening is partially obstructed by the open door panels, thus diminishing full access through the doorway. This is particularly undesirable when the bifolding doors are utilized to close over a closet door opening, for example, where full access to the closet interior is desirable. This limitation on the operational use of bifolding door installations is particularly prevalent when employing hardware of the type described in my U.S. Pat. No. 3,813,730, issued June 4, 1974, for example, wherein the door supporting pivots and track guides are associated with socket mounted anchor means as opposed to more conventional screw fastener mounting. In such socket mounted hardware the mounting sockets are bored inwardly of the end edges of the panels, and because of the desirability of utilizing the panels interchangeably for both left and right-hand door installations, it is the practice to locate the axes of the anchor sockets at uniform distances from the lateral panel edges. Preferably the socket boring operation is carried out in a factory context by large jig boring machines with the hardware being installed either at the factory or the jobsite. Within the aforenoted parameters of practice, it will be understood that the pivot axes for the pivotally supported panels and the axis of the track guide rollers or pins on the non-pivotally supported guide panels are normally located like distances from the lateral door margins or edges. That being the case, the geometrics of the door folding or opening operations are such that the open position angle of the door panels, that is, when the doors are in fully opened condition, is restricted to one of substantially right angles with respect to the overhead guide track. As pointed out above, this restriction seriously limits full acess to the door opening.
Ancillary to the above, is the further problem attending closing operation of the door panels. Briefly, it is typical practice for the user to apply pressure to the jamb or pivot mounted panel to initiate door closing movements and in fact operating handles or knobs are oftentimes provided on such panels for that very purpose. However when the guided door panel is positioned at right angles or near right angles to the door track, closing pressure applied to the pivoted panel oftentimes causes the guide pivot to bind in the track, thereby preventing or hampering smooth door closing movements. Of additional importance in this respect is the attendant possibility of seriously damaging and bending the pivot hardware or dislocating the pivot axis from its adjusted location. All this leads to eventual breakdown and loss of smooth operational functioning for the door installation.